RPE catalyzes the reversible epimerization of D-ribulose 5-phosphate to D-xylulose 5-phosphate . This reaction is vital for the non-oxidative phase of the pentose phosphate pathway, which is involved in the regeneration of ribose-5-phosphate for nucleotide synthesis and the production of NADPH for reductive biosynthesis .
RPE is a metalloprotein that requires metal ions for its activity . The enzyme typically forms a homodimer, and its structure includes a TIM barrel, which is a common fold in enzymes that catalyze reactions involving carbohydrates . The structural integrity and function of RPE are highly dependent on the presence of these metal ions.
The pentose phosphate pathway, where RPE is a key player, is crucial for maintaining cellular redox balance and providing ribose-5-phosphate for nucleotide synthesis . This pathway also contributes to the production of erythrose-4-phosphate, which is a precursor for the synthesis of aromatic amino acids .
Mutations in the RPE gene have been associated with various metabolic disorders. For instance, defects in this enzyme can lead to Charcot-Marie-Tooth Disease, Axonal, Type 2Dd and Bartter Syndrome, Type 1, Antenatal . These conditions highlight the importance of RPE in normal cellular function and metabolic processes.
Recombinant RPE is produced using genetic engineering techniques to express the human RPE gene in a host organism, such as bacteria or yeast . This allows for the large-scale production of the enzyme for research and therapeutic purposes. Recombinant RPE is used in various biochemical assays to study its function and to develop potential treatments for metabolic disorders.